Methanol → 2,3-Dihydro-1,4-phthalazinedione

HRID 550113Notes

Reaction equation

HRID 550113 reaction equation
ClC1C(C[N:9]2[C:17](=[O:18])[C:16]3[C:11](=[CH:12][CH:13]=[CH:14][CH:15]=3)[C:10]2=[O:19])=NC=CN=1.[NH2:20]N.CO>C(Cl)Cl>[C:10]1(=[O:19])[C:11]2[C:16](=[CH:15][CH:14]=[CH:13][CH:12]=2)[C:17](=[O:18])[NH:9][NH:20]1

Participants

5

Reactant 3

HCID 887MethanolHCID 9321HydrazineHCID 576810332-((3-Chloropyrazin-2-yl)methyl)isoindoline-1,3-dione

Product 1

HCID 2194012,3-Dihydro-1,4-phthalazinedione

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

A solution of 2-(3-chloropyrazin-2-ylmethyl)-isoindole-1,3-dione (10.0 g, 36.5 mmol) in anhydrous CH2Cl2 (200 mL) was charged with hydrazine (2.87 mL, 2.93 g, 91.3 mmol, 2.5 eq.) at rt, under N2 atmosphere. After 2.5 h, MeOH (300 mL) was added and the reaction was heated until the solution was homogenous. The reaction mixture was allowed to stir for 19 h. The white ppt that had formed (2,3-dihydrophthalazine-1,4-dione byproduct), was filtered off and washed several times with ether. The clear filtrate was concentrated in vacua and the concentrate was dissolved in EtOAc and filtered again to remove white ppt. All solvent was removed, giving a yellow oil, which was dissolved into EtOAc and ether and charged with HCl (g). The title compound, a pale yellow solid, instantly precipitated. The title compound was dried in a 40° C. oven for 72 h, affording the title compound, as a dark yellow solid; 1H NMR (400 MHz, CD3OD) δ 4.55 (2 H, s), 8.27 (1 H, d, J=2.52 Hz), 8.54 (1 H, d, J=2.56 Hz); MS (ES+): m/z 143.96/145.96 (100/60) [MH+]; HPLC: tR=0.41 min. (OpenLynx, polar—7 min).

Workup

  1. temperaturethe reaction was heated until the solution

Sources & evidence

ORD record
ord-50cb83ca40cd4b2aaab8ffb1b8a61301
Source dataset
uspto-grants-2011_05
Patent number
US07943767B2

Reaction notes

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